Maurice of Nassau (Dutch: Maurits van Nassau) (14 November 1567 – 23 April 1625), Prince of Orange (1618–1625), son of William the Silent and Princess Anna of Saxony, was born at the castle of Dillenburg. He was named after his maternal grandfather, the Elector Maurice of Saxony.Maurice never married but was the father of illegitimate children by Margaretha van Mechelen and Anna van de Kelder. He was raised in Dillenburg by his uncle Johan of Nassau (Jan the Old). Together with his cousin Willem Lodewijk he studied in Heidelberg and later with his brother Philip in Leiden where he met Simon Stevin. The States of Holland and Zeeland paid for his studies, as their father had run into financial problems after spending his entire fortune in the early stages of the Dutch revolt.Only 16 when his father was murdered in Delft in 1584, he soon took over as stadtholder (Stadhouder), though this title was not inheritable (The monarchs of England and France had refused, and there simply was no one else to take the job). He became stadtholder of Holland and Zeeland in 1585, of Guelders, Overijssel and Utrecht in 1590 and of Groningen and Drenthe in 1620 (following the death of Willem Lodewijk, who had been Stadtholder there and in Friesland).Maurice was preceded as Prince of Orange (not a Dutch title) by his elder half-brother Philip William. However, Philip William was in the custody of Spain, remaining so until 1596, and was thus unable to lead the Dutch cause.

Maurice of Nassau (Maurits van Nassau) was born on 14 November 1567 as son of Willem of Nassau and Princess Anna of Saxony, at the castle of Dillenburg (Germany). Maurice was raised in Dillenburg by his uncle Johan of Nassau (Jan the Old), lateron his life he studied in Heidelberg (Germany) and in Leiden.

The year following the murder on his father, Maurice was elected stadtholder in his stead. Under his presidency (1585-1625) the power and wealth of the Republic rapidly increased, active hostilities were frequently undertaken against the Spaniards, and the Dutch East India Company was formed (1602). Meanwhile, however, there arose serious dissensions between the democratic and the government parties, which were greatly aggravated by the pernicious theological controversies of the Arminians and the Gomarists.

Contrary to the sound advice of the stadtholder Maurice, John van Oldenbarnevelt, Grand pensionary or chancellor of Holland, concluded a twelve years' peace with Spain in 1609. Incensed by the quarrels which now ensued, Maurice caused Oldenbarnevelt, then in his 72nd year, to be arrested and condemned to death by a partial tribunal in 1618, but by this judicial murder he did not succeed in intimidating his refractory subjects.

Maurice died in 1625, and was succeeded by his brother Frederick Henry (1625-1647), under whom the unity of the Republic became more consolidated, and the prosperity of the States reached its climax.

Maurits never married, but fathered several bastards by Margaretha van Mechelen, Anna van de Kelder and others. Many of these descendents were elevated to Reichs Counts of Nassau-Le Lecq and Nassau-Beverweerd. He also had children with at least 3 other women. Those children received lower titles like Lord and Lady of the Lek.

The two most well-known sons were:

- Willem (~1601-1627) married 1627 Anna van der Noot (†1642), lady of Hoogwoud. He had a bastard son by Barbara Cocx.

- Lodewijk (1602-1665), lord of Beverweerd, married 1630 Isabella of Hornes (†1664). This line of Nassau-Le Lecq became extinct in 1861.